Spiranthes spiralis
Autumn Lady's-tresses
Spirodela polyrhiza
Greater Duckweed
Stachys alpina
Limestone Woundwort
Stachys arvensis
Field Woundwort
Stachys byzantina
Lamb's-ear
Stachys germanica
Downy Woundwort
Stachys palustris
Marsh Woundwort
Stachys sylvatica
Hedge Woundwort
Stapelia variegata
Staphylea pinnata
Bladdernut
Stellaria alsine
Bog Stitchwort
Stellaria aquatica
Water Chickweed
Stellaria graminea
Lesser Stitchwort
Stellaria holostea
Greater Stitchwort
Stellaria media
Common Chickweed
Stellaria neglecta
Greater Chickweed
Stellaria palustris
Marsh Stitchwort
Sternbergia lutea
Winter Daffodil
Stuckenia pectinata
Fennel Pondweed
Suaeda maritima
Annual Sea-blite
Succisa pratensis
Devil's-bit Scabious
Symphoricarpos albus
Snowberry
Symphyotrichum lanceolatum
Narrow-leaved Michaelmas-daisy
Symphytum asperum
Rough Comfrey